The present invention relates to the retention of snow and ice on the roofs of buildings. More particularly, the present invention is directed to a snow retention apparatus that attaches to roofs to form a fence-like structure that prevents snow and ice from sliding off of the roof in large pieces, and a method of installing such an apparatus.
For roofs commonly used in buildings, such as office buildings, barns, and residential houses, it is desirable to incorporate a frame structure on the roof, especially roofs with steep pitches. The frame structure is able to control the movement of snow and/or ice on the roof by obstructing the snow and/or ice. It can also be used as a safety device, to which workers can secure themselves using harnesses to protect against sliding off of a building""s roof.
When used for snow/ice retention, the frame structure prevents the pitch of the roof from causing the snow and/or ice to slide off of the roof in large pieces. Snow and/or ice can only form pieces that fit within openings of the frame structure and the thickness of pieces sliding off of the roof is limited to the height of the frame structure above the roof""s top surface.
Snow or ice sliding off of a roof, especially in large pieces, can be dangerous to people near the building, and it can damage property items (e.g., cars); natural landscape features; other components of the building (e.g., gutters, antennas, satellite dishes, etc.); and utility lines; among other items situated near the building. Large pieces of snow and ice frequently slide off of metal roofs, such as standing seam metal roofs, which can result in bodily injury and/or damage.
Standing seam roofs, which may be made out of metal or other suitable materials, are used in various structures, usually soaring structures, such as churches, cathedrals, barns, and industrial buildings. The points where roof panels are connected form raised seams; the seams generally run parallel along the roof. The top surfaces of metal seam roofs are often smooth, lacking the friction associated with roofs made of asphalt shingles and similar roofing materials. The smoothness increases the danger associated with the roof by facilitating the sliding of snow and/or ice and increasing the likelihood that workers on the roof will slip or slide on the roof.
Various mechanisms have been used as frame structures to prevent snow and/or ice from sliding off of roofs. These mechanisms have included brackets attached to the roof, including snow stop hardware, such as flags attached to frames. In addition, frame structures have been formed by passing cylindrically-shaped rods or other posts through the brackets. In those frame structures, rods or other posts prevent the snow and/or ice from forming large or thick pieces that can slide off of the roof.
Although in some instances, frame structures have been held onto the roof by a series of wires linking brackets on the roof, i.e., a net-like configuration, in many instances, the brackets of the frame structure have been permanently attached to the roof with nails, screws, or bolts. Also, the frame structures have been attached to the roof by passing hook-like supports around the lower edges of slate or shingles; the supports are set into the roof board by screws, bolts, or spikes. The nails, screws, bolts, and spikes used to attach frame structures to a roof penetrate the roofing material which can cause leaking and other problems. Also, these types of fasteners require permanent installation of the brackets, such that if the brackets are removed, the roof must be repaired.
With standing seam roofs, there have been attempts to attach a frame structure to the roof using a friction fit on the seams and/or by deforming the seams for better adhesion to the brackets used in the frame structure. The frame systems previously used with standing seam roofs have incorporated their snow retention rail systems at a height above the roof seams. Thus, this height for the rail system would allow a build up of snow and/or ice up to or above the level of the seams of the roof, i.e., up to the height of the rails. The conventional snow retention systems have not provided rails or posts at or below the level of the seams.
In addition, with conventional rail systems, the cylindrically-shaped rails or posts, which primarily function to control the snow and/or ice on the roof, must be threaded through holes in the brackets before or after installation of the brackets. Threading of the rails or posts through such holes on the roof can be difficult and dangerous. Also, changing the positioning of the rails or posts is very difficult, and the holes in the brackets may not allow for versatility in rail or post placement. Further, the cylindrically-shaped rails or posts do not have the force resistance of posts having a more squared shape.
There is a continuing need for a snow retention rail system for roofs in which there is versatility in the placement of rails, rails are at or below the level of seams on roofs, and rails are square, rectangular, triangular, D-shaped, or similarly shaped.
The present invention comprises an apparatus for retaining snow and/or ice on a roof, thus preventing large pieces from sliding off of the roof and causing damage, and a method of installing such an apparatus. In its most general form, the apparatus of the present invention comprises clamping brackets secured to a roof and having slots or pockets in which rails are seated. The rails pass through two or more clamping brackets lined up on the roof. The clamping brackets and rails are made of material which provides suitable structural integrity, such as ferrous or non-ferrous metals, aluminum, steel, alloys of aluminum or steel, Kevlar, bronze, bronze alloys, polycarbonate and other plastic resins.
In one embodiment, the clamping brackets form a channel for placement on the seams of metal seam roofs. The clamping brackets are secured to the seams of the roof through a friction fit. The friction fit may be created by opposed blunt-end and cupped screws passed through apertures on either side of the clamping brackets to contact the seams.
In another embodiment, the apparatus of the present invention can be used with roof systems other than seamed roofs, such as slate, tile, metal roofing, cementious synthetic roofing materials, or membrane roofing fabrics. With these roof systems, the clamping brackets are fastened directly to the roof surface or are attached to a plate, bar, or strap that is connected to the roof surface.
In one embodiment of the method of installing the apparatus of the present invention, the rails are placed into the pockets or slots of the clamping brackets and are secured by gravity, a retention apparatus, such as a clip or wedge, and/or a suitable adhesive.
In an alternative embodiment, the apparatus of the present invention comprises a fence-like frame structure installed on roofs for providing support for workers on the roof.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention.